The impressive Church of St. Nicholas, now the main temple of the Protestant Hussite Church, is in the Old Town Square. The temple erected in the first half of 18 century is one of the most famous masterpieces of the Baroque architecture of Prague. 

Kilián Dientzenhofer was the author of the temple project featuring the central dome and two tall towers. But later the temple was rebuilt and decorated. The interior of the temple is richly decorated with gold-plating. A large chandelier, the gift of the Russian Emperor Alexander II, hangs in the center of the main nave of the temple. 

After the Holy Roman Emperor Joseph II signed the Edict of Tolerance in 1782 many religious institutions were closed including the Church of St. Nicholas on the Old Town Square. The church building was used for various economic needs and gradually crumbled. However, in the period from 1870 through 1914 the church, which was then rented by the Russian Orthodox Church, was completely restored and religious services were held there.

The monument of Jan Hus, a national hero of Czechia, is near the Church of St. Nicholas on the Old Town Square. The monument was placed there in 1915. Jan Hus was an inspirer of the Czech Reformation who stood at the origins of the Czech protestant movement.